Wet-chemical synthesis of ‘snow stone’ chiolite Na5Al3F14:Ce3+,Gd3+ UVB emitting phosphors

•UVB-emitting Na5Al3F14: Ce3+, Gd3+ phosphor synthesized by wet chemical route.•Na5Al3F14: Ce3+, Gd3+ is a good phosphor for UVB applications.•The co-doped Ce3+ to Gd3+ can increase the energy transfer efficiency. Synthesis and characterization of Ultraviolet B (UVB) emitting phosphors based on hitherto unexplored Na5Al3F14 host activated with Ce3+ and/or Gd3+ are presented. These phosphors were easily synthesized by wet chemical process while the conventional solid-state procedures are known to fail in producing phase pure composition. Powder XRD confirms tetragonal structure with P 4/m n c space group. Both Ce3+ and Gd3+ yielded intense UVB emission. Further, Gd3+ emission was enhanced by Ce3+→Gd3+ energy transfer. Ease of synthesis, efficient emission in a narrow spectral region, broad excitation bands render Na5Al3F14 :Ce3+ , Gd3+ phosphors as promising materials for designing UVB light sources. [Display omitted]